Diesel-type engine for toy aircraft



Sept' 16, 1952 K. o. WOODRUFF ETAL y2,610,616

DIESEL-TYPE ENGINE FOR TOY AIRCRAFT Filed Oct. 21, 1946 Patented Sept.16, 1952 DIESEL-TYPE ENGINE FOR TOY AIRCRAFT `Kenneth 0. Woodruff,Englewood; and Robert L. Krier, Walsenburg, Colo.

Application October 21, 1946, Serial N o. 704,604

`rThe present inventionl relates to a single cylinder diesel-type enginefor toy aircraft. It has to do particularly, although not exclusively,with a single cylinder air-cooled diesel-type engine of extremely smallsizel and of extremely f light weight capable of propelling a toy orminiature aircraft, in whichthe engine is of the combustion-ignitiontype having no electric sparking arrangement. The principle could, ofcourse, be used also with a multi-cylinder engine. y

One of the vobjects of they present invention is to'provide an engine ofthe foregoing character having a novel arrangement of parts, as well asa minimum number of parts, whereby to provide a compact engine structureof relatively small size and extremely light weight which is capablevoi. being manufactured at relatively low cost, and

one which will turn up at a maximum number of R. P. Ms.

A further object of the present invention is to provide novel airintake-adjustment and adjustment-maintaining means for an engine of theforegoing character; it being anotherv and important object of theinvention to provide new and novel means for varying the displacement ofthe engine cylinder above the reciprocable piston located therein.

' Another and important object of the present invention Ais to providean efficient, compact, andv light weight engine of the foregoingcharacter which operates on the diesel principle and which is of thecombustion-ignition type and therefore does not employ any sparkingarrangement.-

` The foregoing and other objects and advantages of the presentinvention will be apparent from the vfollowing description and appendedclaims when considered in connection with they accompanying drawingsforming a partof this specification, wherein like reference charactersdesignate corresponding parts in the several views. 1

In said drawings:

Fig.Y l is a longitudinal vertical sectional view throughv an engine'embodying the present invention. y

Fig. 2 is a fragmentary elevational view taken substantially along theline 2-2 of Fig. 1,'looking inthe direction of the arrows; and Y Fig'. 3isa fragmentary transverse vertical sectional view taken substantiallyalong 'the lineA not limited in its application to the details of 3Claims. (Cl. 123-73) 2 construction and arrangement of/partsillus-4trated in the accompanying drawingfsince the invention is capable ofother embodiments and of being practiced or carried out in various ways.Also it is to be understood that the phraseology or terminology employedherein is forthe purpose of description and not of limitation, and itisnot intended to limit the invention claimed herein beyond therequirements of the prior art.

Referring now particularly to the drawings, the diesel-type engine vofthe present invention comprises a cylinder I0 mounted upon a' crankcase, shown as a wholeat I I, the crank casa-as shownr comprisingsections I2 and I3 which are thread,-

edly joined together at I4. One end of the crank case is provided with aremovableV cap or cover l5 having an opening therein'to permit access toa drain or inspection plug I6. The section I3 of the crank casecomprises a -vertical wall I'I having a right angularly and horizontallydisposed tubular projecting portion I 8 which carries a bearing for lacrank shaft or propellershaft, shown as a whole at I9; The wall I'I ofthe crank case carries'a bronze bushing or bearing sleeve 2li for thecrank shaft. A

Attached to the section I3 of the crank case and extending Youtwardly inline therewith is a fuel tank 2I having an outer,v closure wall or disk22 which, as shown, is threaded at 23 onto the, portion I8 of the crankcase. A breather plug or venting member 24 is, as shown, threaded intothe wall of the fuel tank. e

The crank shaft I9 has a reduced portion ISa which carries a propeller25 and an outer Ithreaded end portion |91)` which receives a nut '26 tohold said propeller rigidly into engagement with the rotatable spacerring or disk 21 which is disposed between thev propeller 25 and the endwall I8. The outer end of the crank shaft or propeller shaft carries astreamlined spinner or cap member 28 which is recessed at 29 toreceive'v the nut 25 and which is internally threaded at 30 to engagethe threaded end I9b of the shaft. They spinner is preferably formedfrom plastic so as to reduce thewweight of the engine assembly.`

The inner endi ofthe crank shaft` I9 is connected, through a connectingrod 3l, to a piston 32 which reciprocates in a liner or sleeve 33 which'is pressed into thecylinder I0. The sleeve or liner 33 is spacedfrom'the wall Illa of the cylinder to provide an intakeor inductionpassage 34 communicating with an intake port 35 formed in the liner, seeFig. 1. The-liner is'also provided with a pair of preferably opposedexhaust ports 36 (one such being shown in Figs. 1A and 2) whichV portsare in communication with outwardly projecting and preferably oppositelydisposed exhaust pipes or passageways 31 which, as shown in Fig. 2, forman integral part of the walls of the cylinder lll. The upper portion ofthe walls of the cylinder l is threaded at 38 and is preferably shapedto provide an annular shoulder 39, Figs. l and 2. Y

The cylinder I3 is provided with an adjustable cylinder head, shown as awhole at 40, the head being provided with an annular groove 4| in itsunder side to receive the upper end of the sleeve or liner 33. Thecylinder head 40 is provided with a series or plurality of heatdissipating and thus cooling fins 42 and has a cylinder .head operatingor manipulating member 43 having ,n'ger gripping pieces or extensions43a, which member is pressed into a socket formed in the head 40 andwhich is disposed entirely externally of the cylinder and head. Thecylinder head 4U has a The mixturelof fuelandair, providing thecombustible mixtureffor. c ip'erating the combustionignition. typeengine of the present` invention, are bothfpreferably'admitted to theengine cylinderlthrough the crankcase thereof.. To provide meansfcradmitting air, the section I3 yof the crank caselis extended upwardlyat l5 and is provided with an aperture or opening iE-formed therein. Atubular sleeve-like member 41. having a head 48 ,and anotchedrperiph'ery v49 is telescoped-within the extension ,45 .and hasan opening or aperture 53 formedv therein which is adapted to .registerwiththe 4opening Vor :port 46, see Fig. l. It will be .understoodthat byrotating the member 4l., the size ofthe openingfprovided by the alignedports 46 and 5B may be Varied to control or regulate the amount of airadmitted to the engine. To maintain the .parts in their proper adjustedpositions, a spring-like nger 5I Lis provided and is carried by themember or extension 45 toengage in the notches 49 of :the capmember. l.v

As seen clearly in Fig. v1', vthe crank shaft i3 is provided with a portor opening 19a and with lila,Y bore` ISU Vinto thev crankl case andYthence will be drawnup'wardly through the .passageway 34 and port 35injto the cylinder above the piston 32.

It will be understood thatthe proper amount of fuel to air may becontrolled or regulatedto the desired proportions or mixture by virtueof the diameter of the pipe or tube 5.7;, the-bore of the nipple 53, andthe Asize of the Vair-intaker opening provided by the apertures 4.6 and58, sothat the proper and desirable-mixture may be provided.

It will be understood that as the cylinder head 4E! is adjusteddownwardly relative to the fixed cylinder l0, the displacement of thecylinder will be reduced, whereas the adjustment of the cylinder headupwardly, or away from the piston 32, Vwill increase the displacement ofthe cylinder. It will also be understood that the greatest compressionis obtained when the displacement is reduced, that is when the'cylinderhead 43 is in its lowermost position In this position, with the airintake opening set properly,

the propeller 25 is spun rapidly to create suction within `theengineSuch suction draws into 'the cylinder the proper combustible mixture,

. which is compressed and fired by the combustionignition principle tostart the engine in operation. After the engine has once been startedand is in operation, 'the cylinder head 40 may be adjusted upwardly oraway from the piston 32 to increase the displacement to approximatelyfour (4)y cubic .centimeters for normal operation. With thissetting, the`improved engines of the present invention will develop up toapprox-imatelyvOOR; P. M. Y 1

The entire novel engine structure loi the pres*- ent inventionmaybequickly and readily assembled lor disassembled andwill produce the=necessary power for propelling ininiatu-reorvtoyaircraft on relativelylong-sustainediiights Y The various parts making l.upthepresent novelengine lstructure are formed .from'material which is best suited to theparticular .design or par-t, some of the parts being machined .fromhamaluminum whereas others, such as thepiston 32 cylinder head 4d,arepreierablfgiormed from steel. The spacer-ring or; disk 21 vmay beformed either from steelor aluminum and,` as. stated above, the spinner2.8 is preferably formed from plastic although, if desired, it may beformed from a block of hard aluminum, or vsirnilarliglit weightmaterial. A

Having thus described the invention what is claimed is:

1. A'two-stroke cycle` internal combustion engine of the compressionignition typefor use-in miniature aircraft comprising aY-crank case, ahollow crank shaft projecting into the crank case, means for 'passing acombustible fuel-air mixture into the-crank Vcaseffthrough the crankshaft,-a cylinder on the crank case having an inlet and an an exhaustport butgotherwise ,imperfora'te, a Vpiston Yreciprocal. in thevcylinder to;

successively seal and opensaid ports, a connectingy rod` connecting thepiston to the crankv shaft, a solid imperioratey cylinder head having anintegral thickened central portion projecting down- Wardly'intothecylinder in sealing engagement therewith and askirt portionthreadedly en.-

Vgagirng the outer'portion of saidcylinder for-axial adjustment of vthecylinderA head, whereby the compression ratio and therefore theignitiona fueltankconcentric with the crank case, a hollow crankshaitextending through the fuel tank into the crank case, an air hornextending inwardly into. communication with a port formed in a Wall of'the crank case for drawing a fuelair mixture -through'the crank shaftinto the.

5 crank case, a fuel nozzle in the air horn, a tube in the fuel tankconnecting the inner end of the fuel nozzle with the lower portion ofthe fuel tank, an

adjustable means for varying the quantity of vand the crank shaft, andmeans for adjusting the ignition timing and compression ratio of theengine including an imperforate cylinder head sealing thev top of thecylinder, said cylinder head having a groove for slidably receiving theupper end of the cylinder and an external skirt threadedly engaging theexternal portion of the cylinder. f

3. A two-stroke cycle internal combustion engine of the compressionignition type for use in miniature aircraft comprising a crank case, afuel tank concentric with the crank case, a hollow crank shaft extendingthrough the fuel tank into the crank case, means including a fuel nozzleextending inwardly into communication with an opening formed in a wallof the crank case for drawing a fuel-air mixture through the crank shaftinto the crank case, conduit means in the fuel tank connecting the fuelnozzle with the' fuel tank, means for controlling the quantity of airdrawn through the crank shaft, a cylinder on the crank case imperforateexcept for inlet and exhaust openings, the inlet opening communitatingwith the crank case, a piston reciprocal 6 in the cylinder, a connectingrod connecting the piston and the crank shaft, and means for adjustingthe ignitionk timing and compression .ratio of the two-stroke cycleinternal combustion en-V gine, said last-named means including animperforate thickened cylinder head sealing the top of the cylinder,said imperforate thickened cylinder head having a groove forcsldablyreceiving the upper end portion of the cylinder and an external coolingfin-carrying skirt threadedly engaging the external portion of thecylinder. i

' KENNETH O. WOODRUFF.

ROBERT L. KRIER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS switzerland A Dec. 17, 1928

